System and method for digital program insertion in cable systems

ABSTRACT

Alternative approaches to the insertion of local commercials and messages into networks feeds are provided. Embodiments include digital commercial insertion for cable operators and others that not only offer more flexibility and features, but may also be significantly cheaper to implement. The actual “insert” of the local commercial or message into the digital program is performed by a standard set top box, with several methods of providing the local commercial to the set top box at the proper insertion time. Another embodiment allows a cable operator to significantly save on equipment in the form of splicers and ad inserters, by allowing easy and dynamic mapping of local commercials to insertion zones.

RELATED APPLICATION

The present application claims the benefit of U.S. ProvisionalApplication No. 60/600,664 filed on Aug. 11, 2004, which is incorporatedherein by reference.

FIELD OF THE INVENTION

This invention is directed towards digital media transmission, and moreparticularly towards transmission of digital programs to end viewers.

BACKGROUND

Cable operators use their infrastructure to carry programming contentand deliver (sell) this to their subscribers. As part of theiragreements with some programmers, the cable operator can also be allowedto insert commercial messages in those network feeds. The operator istypically allowed to do that only at selective times (sometimes called“local avails”, “avails”, “local breaks”, or “breaks”), typically 1-3minutes per hour. The operator can choose to either sell this time toadvertisers (generating extra revenue), or use the time to insertpromotional messages for their own products and services.

Cable operators have used the following set up illustrated in FIG. 1 toimplement local commercial insertion. The programmer typicallydistributes their feed via satellite 22 to the various cable operators.The feed can be analog or even digitally encoded. The feed containssignals (in the form of audio tones called “cue tones”) that indicate alocal break to the cable operator.

The receiver at the cable operator receives the satellite signal 20(decompresses it in case of a digital signal), strips off the audiotone, passes through the (analog) feed 24 to the ad inserters 26, and(separately) passes the Insertion (Control) Signal 25 to the ad inserteras well (triggered by the cue tone in the feed). The Traffic & Billingsystem 28 is responsible for scheduling the commercial messages acrossthe day, it feeds schedule files to ad inserters 26 (typically once aday) with today's insertion schedules.

Separately (and typically at least one day before airing), thecommercial messages are loaded into the ad inserters 26 (this can beencoded from tape, or transcoded from a digital format).

The ad inserter 26 as shown in FIG. 2A typically just “passes through”the incoming analog feed, but whenever it gets an “insert” signal, asshown in FIG. 2B, it looks in its schedule to see which message shouldbe inserted, then looks up the message in its internal database 30, andinserts the message into the (analog) feed.

Messages can be any length (as long as they fit in the “avails” that areagreed upon between the programmer and operator), but typical lengthsare 30 second, 60 seconds, or 15 seconds.

Cable operators typically have the right to insert local messages on avariety of different networks. In addition to this, typical cablesystems consist of multiple ad insertion zones (or ad insertion headends). So if a cable operator serves an area (say a city) that consistsof <n> insertion zones, and wants to insert commercial messages on <m>different networks, a total of <n>×<m> ad inserters are needed. Thisenables the operator to insert unique (different) commercial messages ineach zone/network combination, but at a high cost for equipment.

With the introduction of digital television, cable operators now need toupgrade their insertion infrastructure in order to be able to insertcommercial messages into already compressed (digital) feeds. This newsystem (called DPI, or Digital Program Insertion) is illustrated in FIG.3. The programmer typically distributes their feed via satellite 22 tothe various cable operators. The feed is digitally encoded. The feedcontains signals (in the form of special messages, such as the “SCTE 35”messages that are standardized for this purpose by SCTE) that indicate alocal break to the cable operator.

The receiver at the cable operator receives the satellite signal andpasses it through (including the digital messages) to a new devicecalled a splicer 34. The splicer 34 (among other things) will detect thedigital messages in the stream 33, and start an interaction with thedigital ad server 36 to get a digitally encoded commercial that is readyfor insertion, it will then “splice” that digital commercial into thedigital feed 33 during the local avail. The output signal 38 will be adigital signal with a local commercial during the local avail, and isdistributed to digital reception devices at the consumers premises(typically a digital set-top box, or a digital TV set).

One of the reasons why digital insertion is more complex, is thatinsertion (splicing) of a digital commercial in a digital feed is not asstraightforward as the simple “switch” that is embedded in the analog adinserter 26 (see FIG. 2). Instead it needs a fairly sophisticatedsplicer 34, which is typically external to the ad inserter 26.

Scalability for digital insertion is similar to analog insertion, if acable operator serves <n> insertion zones, and wants to insertcommercial messages on <m> different digital networks, a total of<n>×<m> ad inserters and splicers are needed. Again, this enables theoperator to insert unique (different) commercial messages in eachzone/network combination.

One of the trends in local cable advertising is to combine all adinsertion zones and capabilities into a single “Interconnect”. AnInterconnect typically covers a complete city and may consist of onecable operator, or even a combination of multiple cable operators. Itessentially connects all ad inserters so that a client (e.g. anadvertiser) can approach the whole market as a single entity, can placesingle orders, and there is a single T&B (traffic and billing) systemdriving the insertion schedules. In addition the technical part of theinterconnect is typically run from a single command location (MasterControl Center). If an Interconnect covers <n> zones, it has the abilityto (in any given local avail) air <n> different commercials at the sametime in the same program.

There is a large cost involved in converting to digital. Cable operatorsthat “go digital” (in other words: start to distribute their signals totheir subscribers in digitally compressed format) obviously facesignificant investments in infrastructure, digital set-top boxes orother CPE, etc. But on top of these, there is another requiredinvestment which is sometimes overlooked, namely the equipment that isneeded to insert commercial messages into compressed (digital) programfeeds. For a market that contains <n> zones and <m> digitally carriednetworks, this may add up to <n>×<m> splicers and <n>x<m> digital adservers, which can be a significant investment.

Therefore, many operators consider “collapsing” their insertion zones tosave money (e.g. collapse <n> zones into one (or few) big insertionzones). This reduces investment, but also reduces the unique ability toinsert different commercials in different zones (which advertisers canuse for reasons of better targeting their messages).

SUMMARY

The present invention provides some alternative approaches to digitalcommercial insertion for cable operators and others that not only offermore flexibility and features, but may also be significantly cheaper toimplement. In one embodiment, the present invention includes a systemwhere the actual “insert” of the commercial or message into the digitalprogram is actually performed by the digital receiver that sits at theconsumer's premises (this can be a set-top box, digital TV set, orother). This strongly reduces the need for sophisticated splicer andad-server equipment at the head-end, while imposing minimal to noadditional cost at the receiver devices.

In another embodiment, the present invention includes a system where theactual “insert” of the commercial is performed upstream (for example, atthe head-end), yet the number of unique splicers and ad servers isgreatly reduced, while preserving the ability to send insert differentcommercials in different insertion zones.

The present invention includes a method of inserting local commercialsinto a local feed, including receiving and distributing a digital mediastream to a plurality of digital reception devices (for example, set topboxes), detecting a signal in the digital media stream indicating aninsertion point, selecting a digitally encoded commercial for insertion;and sending the digitally encoded commercial to the plurality of digitalreception devices, at a time as indicated by the signal indicating aninsertion point. It further includes providing a signal to at least someof the plurality of digital reception devices to indicate to the some ofthe plurality of digital reception devices to switch to the digitallyencoded commercial. The digital reception devices will switch back tothe digital media stream at a time after an end time of the digitallyencoded commercial. The digital reception devices may be provided withsoftware to facilitate switching to and from the digitally encodedcommercial, or may be hardcoded with firmware, Asics etc. to allow theswitching functionality.

The step of sending the digitally encoded commercial to the plurality ofdigital reception devices may be performed by multiplexing the digitallyencoded commercial into the digital media stream. Alternatively, it canbe performed by using a feeder channel, or a combination of thesetechniques.

Some of the digital reception devices may receives a different digitallyencoded commercial, depending on the setup of the system. For example, aplurality of digitally encoded commercials may be sent simultaneously tothe plurality of digital reception devices, and a filtering process willfilter out at least one digitally encoded commercial to prevent it frombeing received by a selected group of digital reception devices.

A count may be maintained of a number of times the digital receptiondevices switch to the digitally encoded commercial, and a differentdigitally encoded commercial may provided depending upon the count.

The present invention also includes a system for inserting localcommercials into a local feed. A client ad server component, receives adigital media stream and distributes the digital media stream to aplurality of digital reception devices. When the client ad servercomponent detects a signal in the digital media stream indicating aninsertion point, the client ad server component sends a digitallyencoded commercial for insertion to the plurality of digital receptiondevices, at a time as indicated by the signal indicating an insertionpoint. The client ad server component provides a signal (which may bethe same signal as the signal indicating an insertion point, just passedon through) to at least some of the plurality of digital receptiondevices to indicate to those plurality of digital reception devices toswitch to the digitally encoded commercial. The digital receptiondevices will switch back to the digital media stream at a time after anend time of the digitally encoded commercial.

Another aspect of the present invention includes a system for allowing aplurality of different local messages to be inserted across a pluralityof insertion zones. It includes a plurality of splicing components, onesplicing component for each different local message, wherein theplurality of splicing components receiving a common network feed. Italso includes a programmable switch, having an input port for each ofthe plurality of splicing components, and having an output port for eachof the plurality of insertion zones, wherein the programmable switch iscapable of mapping any input port to one or more output ports. Acontroller controls the plurality of splicing components and theprogrammable switch, to allow a different local message to be providedto a selected ones of the plurality of insertion zones. The controllercan include a prioritizing function to determine the best allocation oflocal messages to insertion zones in case there are more local messagesthan splicing components.

This aspect of the invention may also include a initial switch providingthe common network feed to the plurality of splicing components, theinitial switch to provide for changing the common network feed to anetwork feed which will subsequently include an insertion point forinserting local messages. Before a local message is complete, thecontroller can instruct the programmable switch to cause at least oneinsertion zone to start receiving media from a different splicingcomponent.

An advantage of the present invention include the ability to usepresent-day set top boxes with minimal “intelligence”, for example,without any need for a profiler to help such set top box to decide whichlocal commercial to insert.

Other advantages of the present invention include a more cost efficientway of digital commercial insertion for cable operators and others, butalso an approach that inherently provides more flexibility (for example,there is no reason anymore why commercial insertion zones need to be“hard wired” and not change-able once they are done).

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages of the present inventionwill be more fully understood from the following detailed description ofillustrative embodiments, taken in conjunction with the accompanyingdrawings in which:

FIG. 1 illustrates a traditional local cable ad insertion system;

FIGS. 2A and 2B illustrate pass-through and Ad Inserter mode for atraditional ad inserter;

FIG. 3 illustrates a digital local cable ad insertion (DPI);

FIG. 4 shows an illustrative embodiment of the present invention forClient Insertion;

FIG. 5 illustrates how to insert Commercials Within Multiplex accordingto an illustrative embodiment;

FIG. 6 illustrates how to use Feeder Channel according to anillustrative embodiment;

FIG. 7 illustrates a Shared Feeder Channel example;

FIG. 8 illustrates a Unique Feeder Channels Per Zone example;

FIG. 9 illustrates a Cascaded Approach example;

FIG. 10 is a block diagram of a Client Ad Server Unit (CASU) accordingto an illustrative embodiment;

FIG. 11 is a block diagram illustrating Signal Paths for DigitalInsertion; and

FIG. 12 illustrates an embodiment for Optimized Digital Insertion.

DETAILED DESCRIPTION

The present invention provides a novel solution to allowing localinsertion of content, typically local commercials or ads, into thedigital feed for cable operators and other distributors. The presentinvention may be implemented at several different locations along thedelivery process, either in one location or distributed along thedelivery stream. Although the present invention is described in terms ofcommercials and ads, the present invention can be used for insertion ofany specific media, such as messages intended for a local audience, oreven customized parts of generic commercials, such as the insertion of alocal store location at the end of a generic commercial.

An illustrative embodiment of the present invention focusing on usingSet-top boxes for insertion shall now be described. In this approach,the insertion (splicing) of commercial messages is pushed down to theindividual digital set-top boxes 44 as illustrated in FIG. 4. Theprogrammer distributes their (digitally encoded) feed (including SCTE 35or other switch messages to signal local avails) via satellite 22 (or byother method) to the various cable operators. The receiver 32 at thecable operator receives the satellite signal and passes it through(including the digital switch messages) to a new device called “ClientAd Server” 40.

The Client Ad Server 40 stores commercials for later play out. Typicallysuch commercials are already in digital form, and compressed. The ClientAd Server 40 also communicates with the Traffic & Billing system 42 sothat it understands which commercials are schedule for each local avail.Whenever the Client Ad Server 40 detects a digital insert message (e.g.SCTE 35 message) in the stream 33, it does the following:

-   -   Locates a commercial that should be “inserted” in this break,        and play it out exactly in sync with the avail (either in the        same multiplex, or on a separate multiplex, as described below).    -   Either passes through the digital insert messages to the set-top        boxes 44 downstream, or alternatively replaces them with similar        switch messages specifically designed to be handled by set-top        boxes 44.

The Set-top boxes 44 are typically ordinary set top boxes, which includespecial switching logic, typically in the form of an embedded softwareapplication. This embedded software may be installed the Set-top boxes44, or alternatively downloaded to the Set-top boxes 44 through thedigital feed 35 or otherwise. The software detects switch messages inthe stream 35, and uses them to “switch” to a local commercial duringthe insertion break. More specifically, in accordance with anillustrative embodiment, at the beginning of an avail the Set-top boxes44 will switch to the local commercial, and at the end of a specifiedlength of time they will switch back to the program feed 35.

When the Client Ad Server 40 plays out the local commercial exactly insync with the local avail of the program it needs to be inserted into,there are two options for provided the commercial to the set-top boxes44. The first option is shown in FIG. 5, where the local commercials arebe played out in the same multiplex as the program feed it needs to be“inserted” into. FIG. 5 illustrates a single (MPEG) multiplexed signal45 that carries six digital program feeds 46 (for this example, ESPN,CNN, USA, TNT, TBS, A&E). These program feeds are merely illustrativeand no claim is made to those networks or any affiliation with any suchnetwork. The multiplex 45 also has two reserved feeds 48 that are onlyused during a local avail on any of the six programs 46. Preciselyduring each of these local avails 50, the reserved feed 48 will carrythe local commercial 52 so that the set-top boxes 44 (not shown) can“switch to” and “switch from” the commercial 52 at the beginning and endof the avail 50 respectively.

This approach requires some bandwidth to be reserved in every multiplex45 that carries digital programs 46 that need local ad insertion. Theamount of bandwidth depends on how many overlapping local breaks 50 canoccur amongst the digital program feeds 46 within the multiplex 35, inthe example there are two reserved feeds 42 so its is possible to handleup to two overlapping avails 50. Other numbers of reserved feeds 42 arepossible and within the scope of the invention. Further, there is someroom for optimization beyond the number for reserved feeds 42, forexample it may be a good idea to concentrate the most valuable programfeeds 46 in few multiplexes 45 that have a relatively high number ofreserved feeds (for example, four), whereas the less valuable programfeeds 46 are carried in multiplexes 45 with lower number of reservedfeeds. This would have the effect that the chances of “losing” an availon valuable feeds 46 is less than loosing an avail on a less valuablenetwork 46.

The second option is shown in FIG. 6 and involves playing the localcommercials in a dedicated feeder channel. FIG. 6 illustrates a number(in this case four) of MPEG multiplexes 45. The first three multiplexes(Mux 1-3) carry regular digital program feeds 46 (depending on encodingand modulation, there typically may be as few as seven, or more thantwelve program feeds in the multiplexes). The fourth multiplex, Mux-4,is reserved for all local commercials, it is also known as the feederchannel.

The regular program feeds contain local avails 50. Precisely during eachof these local avails, the feeder channel Mux-4 will carry the localcommercial 52 so that the set-top boxes can “switch to” and “switchfrom” it at the beginning and end of the avail 50 respectively.

The feeder channel can either be a fully dedicated multiplex/QAM(Quadrature Amplitude Modulation), but it can also be a reserved part ofa multiplex/QAM that is partly also used for other services. The amountof bandwidth that has to be reserved in the feeder channel depends onhow many overlapping local avails the operator wants to be able tohandle with this system. This allocation can be fine-tuned by the cableoperator as a trade off between bandwidth and returns.

Each of these embodiments has certain advantages. The first embodiment,within the multiplex 45 has the advantage very simple implementation inset-top box, and can do a cleaner (seamless) splice even with basicset-top boxes. However, it tends to use more bandwidth and may requiremore sophistication at the head-end, because of the need forre-multiplexing instead of simple play out. The second embodiment, usinga feeder channel, has optimal bandwidth efficiency. However it mayrequire more integration in set-top box software (for example, the needto access the tuner). Also, a seamless splice is somewhat moredifficult, however this can be fixed by having black frames around thecommercial. It is also possible to mix both approaches to achieve thebest combination of simplicity, bandwidth efficiency, and other featuresfor a general solution, and also specific requirements.

Focusing now on the Client Ad Server 40, there are a number of differentoptions on the number and location of Client Ad Servers 40 in the cableoperators network. In a first centralized example, consider a cableoperator in a market that has 50 insertion zones, and 40 networks feedsthat require local commercial insertion. We assume that the cableoperator uses the Feeder Channel approach to preserve bandwidth. Thecable operator may decide to use 40 Client Ad Servers (one for eachnetwork feed) and place them at a central location in the system (forexample the Master Control Center) to feed all insertion zones.

Now let's look at a local avail 50 FIG. 7 in one of the network feeds 46(say ESPN). Let's assume the cable operator wants to insert 10 differentcommercial messages 52 in this local break (one in zones 1-5, one inzones 6-10, etc.). Since there is only one Client Ad Server (not shown)that is shared between all 50 insertion zones, the (bandwidth in the)Feeder Channel 45 d is also shared. In this scenario the individualset-top boxes will be instructed which commercial message to select(which will depend on the insertion zone they are member of).

Turning now to a decentralized option, the system can be implementedwith a Client Ad Server 40 per insertion zone (so for this example,fifty in total). In the same local insertion example (ESPN, tencommercials) each of the Client Ad Servers 40 will only insert onecommercial 52 in the Feeder Channel (namely the one that is intended forits specific insertion zone), as illustrated in FIG. 8. In thisscenario, the set-top box does not need specific (zone dependent)instructions in order to “pick” from multiple local commercials 52,making this implementation simpler.

A final example shown in FIG. 9 provides a cascaded approach, where asingle Client Ad Server 40 per network feed is used in combination witha number of “filter” units 56 downstream to optimize bandwidth usage.This approach puts a single Client Ad Server 40 (per network feed) in acentral location (similar to example 1), which would transmit a feederchannel with all different local commercials in it over the backbonenetwork 54 to each head-end or node 55 (similar to FIG. 7). However atthe head-end or node 55 (where the backbone network terminates and isconnected to the “Last Mile” coax network 58) a special filter 56 stripsthe feeder channel from all local commercials but the one that isrelevant for this insertion head end 55, so the actual feeder channelthat is transmitted to the individual homes looks like FIG. 8. Examplesof filter units 56 may be an existing edge device such as an edge-QAMmodulator, that simply only passes one of the feeder channels through,ignoring all others. It could know which one to pass through byconfiguring it at installation time, so every QAM would be configured to“pass” unique feeder channels). Other possible approaches are alsowithin the scope of the invention.

An advantage of this setup is only one Client Ad Server 40 is needed pernetwork feed, and the Set Top Box does not need specific (zonedependent) instructions for picking the proper local commercial.

An illustrative implementation is a cascaded approach with a feederchannel. In this implementation, a single Client Ad Server Unit (CASU)60 is installed at a central location in the cable operators network(e.g. at the Master Control Center). The CASU 60 FIG. 10 performs thefollowing tasks:

-   -   It passes through all digital program feeds 46 of programs that        have local avails, and detects incoming insert messages (it also        passes these insert messages through, or generate set-top box        specific ones, as previously described).    -   It manages the Central Feeder Channel 62 (which is carried to        each head-end over the backbone network), and plays out all        required local commercials on the Feeder Channel 62 during each        relevant local break    -   It has a network interface 64 for loading/unloading new        commercial messages that it (may) need to insert locally.    -   It has an interface to Traffic & Billing systems 42, so that it        knows which local commercials should be inserted across the        whole market in a specific break. It can also maintain logs of        which local commercials have been viewed a certain number of        times (broken down by zone, if helpful), and can choose to        substitute/rotate through different commercials based on any        desired formula.        The CASU 60 functions as follows:    -   There is an interface 64 for loading new local commercials onto        the CASU 60, and removing commercials off of the CASU 60 when        they are no longer needed. Local commercials are loaded in        digitized form and stored 68. This interface can be driven by an        asset management system, or by a local operator. Local        commercials are given a unique identifier when loaded on the        CASU.    -   The T&B System 42 has a dedicated interface for loading        scheduling information into the CASU 60. This information        basically defines which local commercial needs to be inserted in        which feed under which conditions (time, etc.). The CASU 60        stores this scheduling information in its internal schedule        database 66.    -   Up to forty network program feeds 46 can enter the CASU 60.        Although forty feeds 46 were chosen because cable operators        typically insert into forty networks only, this selection is        arbitrary and can be any number of feeds. These feeds 46 may        contain digital insert messages to signal a local avail. The        CASU 60 will pass through the feeds and whenever there is a        local avail, it will access its internal database 66 to        determine which local commercials need to be inserted, and play        these commercials on the Central Feeder Channel output port 62        exactly during the local avail. In addition it may also be        necessary to send some additional information to the set-top        boxes downstream (either by inserting additional information in        the program feeds, or otherwise), this information may include        where in the central feeder channel 62 the local commercials are        played out. The forty input feeds, forty output feeds, and        central feeder channel output feed can physically be mapped on        connectors such as DVB-ASI, DVB-DHEI, or any other interface. It        is also possible to map/combine multiple logical inputs and/or        outputs into one physical connector.    -   The CASU 60 will also manage bandwidth of the central feeder        channel. For example if the system only has bandwidth to deal        with <n> overlapping local commercials, and there actually are        more than <n> overlapping commercials scheduled, it may either        request additional bandwidth or select the <n> local commercials        that can be served. It can do that based on simple        “First-Come-First-Served” selection, or based upon more        sophisticated algorithms that select the commercials with the        highest value.

A second useful component of this system is a Filter Unit 56 FIG. 9 thatsits in each insertion zone. It simply takes the central feeder channel62 FIG. 10 as an input (containing all different local commercialsduring each break) and strips out all but the one that is intended forthis insertion zone. It produces a Local Feeder Channel that is thentransmitted to the homes (and set-top boxes) in the zone. The filterunit 56 basically makes the Set top box's job simple by avoiding needingthe set top box to have intelligence to pick the correct insertioncommercial.

Another component of this system is a software application that residesin the set-top box 44. The application can be resident or downloadable,it does not have a user interface, does not need a return channel perse, and performs the following functions:

-   -   When started the application goes into “passive mode” and starts        “listening” to digital insert messages in the current program        feed.    -   Whenever an insert message is detected, the location of the        local commercial in the local feeder channel is retrieved.        Examples of retrieval include providing the commercial with the        insertion message, or the commercial can be communicated to the        set top box separately. The application retunes the set-top box        to that local commercial at the start of the local avail, and        tunes back to the original program feed at the end of the local        avail. Typically, this will all be transparent to the user.

Another embodiment of the present invention is based on the notion thatthe current network topology (with individual inserters per insertionzone) is in many cases may be overkill. FIG. 11 shows the signal pathsfor digital insertion in a single program feed by a cable operator thathas <n> insertion zones (for the sake of simplicity each combination ofa splicer 34 and a digital ad server 36 is represented as a single box)

This setup gives the cable operator the ability to insert (in a givenlocal avail) a unique and different local commercial in each insertionzone. In reality however, in most cases the cable operator will eitherinsert the same local commercial in all zones, or only a limited set ofdifferent local commercials mapped on the various insertion zones (forexample in a market with fifty insertion zones, there may be fivedifferent commercials, the first going to zones 1-10, the second onegoing to zones 11-20, etc.). Another way of saying this is that in thetraditional setup of ad insertion (such as in FIG. 11) the system isdimensioned for the worse case usage scenario, but does not takeadvantage of the fact that statistically the cable operator will onlyuse a fraction of that.

An alternative setup for digital program insertion according on anembodiment of the present invention is shown in FIG. 12. This setupallows for a maximum of <m> different local commercials to be insertedacross <n> insertion zones. This setup consists of the followingcomponents:

-   -   A total of <m> splicer/ad-server combinations 34, 36 are set up,        all connected to the incoming program feed.    -   A programmable switch 70 is set up. It has <m> input ports 72,        and <n> output ports 74, and can be programmed to map any input        port onto any combination of output ports. Its input ports are        connected to the output ports of the splicers 34,36. Its output        ports are connected to each insertion zone.    -   A controller 76 is provided. It interfaces with the T&B system        42 on one hand, and with the splicer/ad-servers 34, 36 and        programmable switch 70 on the other hand.        The system operates as follows:    -   The T&B System 42 communicates scheduling information to the        controller 70, who stores this in its internal database.    -   Whenever there is a local avail, the splicers 34 will detect it        (through the presence of digital insertion messages) and inform        the controller 76.    -   The controller 76 will then determine which local commercials        need to be inserted in which insertion zones, and assign each        unique local commercial to exactly one splicer/ad-server 34, 36        pair. The controller 76 will also program the switch 70 so that        the output of each splicer 34 is mapped to the correct insertion        zones.

Because of time and scheduling, the controller 76 typically will know inadvance when a local avail is coming up, and can ‘preprogram’ the switch70 to divide up the interzones by appropriate splicer 34. This setup maybe left in place until a next local avail comes up which has a differentcombination of commercials or insertion zones. Since the splicers 34 arepassive when not inserting local commercials, the system will runnormally during normal broadcast, no matter how switch 70 has mapped thesplicers 34 to insertion zones.

This embodiment is flexible with respect to the choice of the maximumnumber of unique commercials. Obviously a lower number will creategreater cost savings but will also limit flexibility. If in a systemwith fifty insertion zones (n=50) it would be acceptable to set themaximum number of unique commercials to ten (m=10), this system wouldcreate an 80% cost savings on splicer/ad-server pairs when compared withthe traditional setup. Further, it is expandable on an incrementalbasis.

In this embodiment, some of the components may be combined into otherphysical system components. For example the programmable switch 70 maybe a separate unit, or integrated with the controller 76, or even be anintegral part of the network (depending on what network is used todistribute program feeds to the insertion zones, this may already be afeature that is built into that network). It should be noted that it isalso possible to combine these various approaches to create unique tradeoffs between investment, features, etc. It should be noted that thepresent invention can be combined with features described in otherpending commonly owned patent applications, including U.S. patentapplication Ser. No. 09/735,983, entitled Seamless Switching and filedon Dec. 13, 2000; U.S. patent application Ser. No. 10/369,047, entitledSeamless Switching and filed on Feb. 19, 2003; U.S. patent applicationSer. No. 10/192,192, entitled System And Method For Seamless SwitchingOf Compressed Audio Streams and filed on Jul. 9, 2002; U.S. patentapplication Ser. No. 10/423,280, entitled System And Method ForOptimized Channel Switching In Digital Television Broadcasting and filedon Apr. 25, 2003; and U.S. patent application Ser. No. 10/991,674,entitled System And Method For Optimized Encoding And Transmission Of APlurality Of Substantially Similar Video Fragments and filed on Nov. 18,2004; which are fully incorporated here by reference.

Although this description is written from the perspective of a cableoperator, it is straightforward to apply the same approaches to othernetwork operators as well (for example broadcast networks withaffiliates, cable networks with local reception points at head-ends,etc.).

Although the invention has been shown and described with respect toillustrative embodiments thereof, various other changes, omissions andadditions in the form and detail thereof may be made therein withoutdeparting from the spirit and scope of the invention.

What is claimed is:
 1. A system for allowing a plurality of differentlocal messages to be inserted across a plurality of insertion zones,comprising: a plurality of splicing components at a network head-endconfigured to receive a common network feed, the plurality of splicingcomponents comprising one splicing component for each of the pluralityof different local messages, each of said plurality of splicingcomponents comprising an ad server component configured to play out atleast one of the plurality of different local messages, wherein each ofsaid plurality of splicing components are configured to transmit to atleast one of the plurality of insertion zones; a programmable switch atthe head-end having an input port for each of said plurality of splicingcomponents and having an output port for each of said plurality ofinsertion zones, wherein said programmable switch is capable of mappingany input port to one or more output ports; and a controller configuredto: determine an expected local avail message and preprogram theprogrammable switch to divide up the insertion zones by the plurality ofsplicer components, receive a local avail message from said plurality ofsplicer components informing the controller when there is a local avail,determine which of the plurality of different local messages are to beinserted in each of the plurality of insertion zones, assign each of theplurality of different local messages to at least one of the pluralityof splicing components, and control said programmable switch to map theplurality of splicing components to provide the plurality of differentlocal messages to the plurality of insertion zones based on saidassignment.
 2. The system of claim 1 wherein said controller includes aprioritizing function to determine the best allocation of local messagesto insertion zones in case there are more local messages than splicingcomponents.
 3. The system of claim 1 further including an initial switchproviding said common network feed to said plurality of splicingcomponents, said initial switch to provide for changing said commonnetwork feed to a network which will subsequently include an insertionpoint for inserting local messages.
 4. The system of claim 1 whereinbefore a local message is complete, said controller instructs saidprogrammable switch to cause at least one insertion zone to startreceiving media from a different splicing component.
 5. The system ofclaim 1 wherein said ad server plays out the at least one of theplurality of different local messages responsive to receiving an insertmessage.
 6. The system of claim 1 wherein said controller comprises aninternal database configured to store scheduling information.
 7. Thesystem of claim 6 wherein said controller interfaces with a traffic andbilling system configured to communicate the scheduling information tothe controller.
 8. The system of claim 1 wherein each of said pluralityof splicer components detect local avails for at least one of saidplurality of different local messages through digital insertionmessages.